Azo dyes and process of making same



UhllTED STATES PATENT OFFICE.

RICHARD TAGGESELL, 0F BUFFALO, NEW YORK. ASSIGNOR TO NATIONAL ANILINE &, CHEMICAL COMPANY, INC, OF NEW YORK, N. Y. A CORPORATION OF NEW YORK.

AZO DYES AND PROCESS OF M-AKING SAMEY.

No Drawing.

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with one molecule of meta-toluenediamin sulfonic acid (till, NH, \lH Still: 1 2: G l) or one molecule of the meta-toluened1amin sulfoni acid obtained by sult'onating meta-teluonediainin (1H,, NH NH 1 2 1;; with fuming sulfuric acid and combining the intermediate productthus obtained of the formula: 1

on3 i I:N ]N=N--meta-to1uenediamin sulfonic acid '1' $03K i with a suitable unsulionated compound.

It has heretofore been proposed to make azo dyestutl's by combining tetrazotized meta-toluenediamin sulfonic" acid with two molecules of an amin or of a diamin, such as niti'o-phenrlcuediamin or beta-naphthylamin, but such dyestuils have only a limited solubility. It has also been. 1i roposed to combine tetraotized meta-toluenediamin snlfonic acid with two n'iolccules ot a meta- (liamin and, by the further'operation of subjecting the intermediate dyestuffs thus obtained to an after "treatment with two molecules of a diazotizcd aromatic sulfonic acid, to produce a (lyestufi of a sullicient de. gree of solubility.

.The new dyestuffsforming the subject matter of the present invention, which contain a second sulfonic acid group, possesses not only a Very satisfactory degree of solubility, but also a Very remarlmble atlinity for the vegetable fiber, which insures their fastness to washing.

Specification of Letters Patent.

Application fileli September 6, 1919.

Patented Jan. 135, 1920,

Serial No. 322,138.

A further distinct dill'erence and advanage of the dyestull's ol the present invention, as compared with the dyestull's above mentioned, is that the d vc-stuli's above mentioned contain as components bodies which either are not able to take up another diazo compound or have already been treated with a diazo compound. in other words, these dyestufis are not capable. of after treatn'lent on the fiber with diazo compounds; while the dyesluli's of the present intention, on the other hand, contau'iing: as a component one of the two meta-toluenediamin sulfonic acids mentioned, either of whichiis capable of taking up'two diazo compounds, eanbe subjected to after-treatment with diazo compounds on the fiber. This property is increased in the new dyestuffs, if the second component is also one able to take up two diazo compounds, this second component being, for instance, nleta-phenylenediamin,

etc.

meta toluencdiamin, meta amide phenol,

The dyestuffs forming the subject matter of the present invention are dark powters, soluble in water, and dyeing cotton from a. salt bath in orange-brown to reddislrbrown shades of great intensity. They correspond. to the general formula:

(Sodium salt) l R iel bi w-N=Nmeta-toluenetiiamin sulfonic acid I SOSNZL R standing for the residueef an unsul fonated aromatic component, such'as metaphenylenedianiin, or the like.-

On" treatment with diazo compounds (m-clcrably cliazotized nitranilin) on the fiber, the shades are darkened and intensified, and the dyeings made practically abso lutely fast to washin While the development of certain azo dyestnll's on the fiber is Well known in the dyestulf art, nevertheless I consider tha the developed colors, produced by developing the new d yt-rstufls on the fib61,flle likewise new, and that these developed colors, as Well as the colors producedby dyeing with the new dyestutl's without developing, form a part of the present invention.

In carrying out my invention in a practi-.

cal way, I proceed as follows (parts being by weight) 202 parts of meta-toluenediamin sulfonic acid (CH NH NH SO H:l:2 6: 4) are tetrazotized in the well known manner with 500 parts of hydrochloric acid of 20 B. and 138 parts of sodium nitrite. To the ice cold tetrazo solution is added, while constantly stirring, a solution of 2:24 parts of the sodium salt oi meta-toluenediamin sul fonic acid (obtained by sulfonating metatoluenediamin with fuming sulfuric acid.) After about six hours stirring the intermediate product will be finished. This reaction may be accelerated by neutralizing almost completely the free mine al acid present by carefully adding soda carbonate. \Vhen the intermediate product is finished, a solution of 108 parts of meta-phenylenediamin is added, and after 24 hours stirring the mixture is made alkaline with soda carbonate, boiled up, salted out, and the precipitated dyestufi' filtered, pressed and dried. I

The new dyestuil' represents, When ground, a dark powder, easily solubl in hot Water with a brown color. It dyes unmordanted cotton from a salt bath bright orange-brown shades of good lastness. When developed on the fiber with diazotized para-nitranilin the shade changes to a dark brown of almost absolute fastness to washing.

In the example given the meta-toluenediamin sulfonic acid, obtained by suli'onating meta-toluenediamin (CH NH NH 1:2:) With fuming sulfuric acid, may be relaced by ineta-toluenediamiu sulfonic acid, (3H,:NH NH, E: 1:216 4; while the meta-phenylenediamin n'iay be replaced by the following: meta toluenediamin, nitro metaphenylenedian'lin, nitrometa-toluenediamin, chlor meta-phenylenediamin (Cl NH NH :1 l), meta-amido-pheny1, alpha-naphthylamin or beta-naphthylamin, to give dye-stuffs of a very similar character.

I claim: 1. The method of producing new azo dyestuiis, which comprises combining one molecule of tetrazotized meta-toluenediamin sul- SO H N-:N-mela-lolucnediamin sulfonic acid I (sodium salts) N=N-residue of unsulfonated aromatic body repr-esentin dark powders, easily soluble in hot water with a brown color, dyeing unmordanted cotton brown shades of great fastness, these shades on developing on the fiber with diazotized para-nitranilin turning into dark brown shades of almost absolute fastnes to washing, substantially as described.

3. The herein. described dyed fibers, dyed with the herein described new dyestuli's derived from one molecule of the tetrazo compound of meta-toluenediam-in sulfonic acid (CH :NH :NH :80 1B] 226:4), one

molecule of a meta tolueuediamin sulfonic acid and one molecule of a suitable unsul'tonated compomid, said dyestutls correspomling to the general formula:

SO H(W-N=N-metaloluenediamin sulfonicaeid.

=N-residue of unsulfenated aromatic body said dyed fibers representing brown shades of great i'tastness.

In testimony whereof I aliix my signature.

RIGI'I ARI) TAGGESELL. 

